The present disclosure relates to a liquid crystal display device that includes a liquid crystal display element in which a liquid crystal layer is sealed between a pair of substrates with alignment films on opposing faces and a manufacturing method of the liquid crystal display device.
In recent years, liquid crystal displays (LCD) have often been used as the display monitor for liquid crystal television sets, notebook personal computers, car navigation devices, and the like. Such liquid crystal displays are categorized into various display modes (systems) according to the molecular arrangement (alignment) of the liquid crystal molecules that are contained in the liquid crystal layer that is interposed between the substrates. As the display mode, for example, a TN (Twisted Nematic) mode in which the liquid crystal molecules are twisted and aligned in a state in which a voltage is not applied is commonly used. With the TN mode, the liquid crystal molecules have a property in which the positive dielectric constant anisotropy, that is, the dielectric constant of the liquid crystal molecules in the long axis direction is large compared to the short axis direction. The liquid crystal molecules therefore have a structure in which the alignment positions of the liquid crystal molecules are sequentially rotated within a plane that is parallel to the substrate faces, while being aligned in a direction that is vertical to the substrate faces.
On the other hand, there has been growing attention on a VA (Vertical Alignment) mode in which the liquid crystal molecules are aligned vertically to the substrate faces in a state in which a voltage is not applied. With the VA mode, the liquid crystal molecules have a property in which the negative dielectric constant anisotropy, that is, the dielectric constant of the liquid crystal molecules in the long axis direction is small compared to the short axis direction, and a wider viewing angle is able to be realized compared to the TN mode.
Such a VA mode liquid crystal display has a structure in which light is transmitted by the liquid crystal molecules that are aligned in a direction that is vertical to the substrates reacting to a voltage being applied by falling to a direction that is parallel to the substrates due to the negative dielectric constant anisotropy. However, since the direction in which the liquid crystal molecules that are aligned in the vertical direction with respect to the substrates fall is arbitrary, the response characteristics with respect to the voltage may be deteriorated by the alignment of the liquid crystal molecules becoming disturbed by the application of the voltage.
Accordingly, as an approach to regulating the direction in which the liquid crystal molecules fall in response to the application of the voltage, a technique of aligning the liquid crystal molecules from a direction that is vertical to the substrates toward a specified direction (known as conferring a pretilt) by forming a polymer layer with a predetermined structure on opposing faces of the substrates has been developed (for example, refer to Japanese Unexamined Patent Application Publication No. 2002-357830). With such a technique, it is possible for the direction in which the liquid crystal molecules fall when a voltage is applied to be determined in advance, and the response characteristics with respect to the application of the voltage are able to be improved.